NASA pages describing ideas for interstellar travel via
antimatter rockets, `warp drives', wormholes, and the like.
Entertaining speculations, but as Edward Purcell once remarked,
`All this stuff about traveling around the universe in space suits
... belongs back where it came from, on the cereal box.'

You (and your computer) can participate in a search for signals
from extraterrestrial civilizations by downloading and running the
SETI@home screensaver software. SETI@home also has a good set of
links
to other SETI sites.